title: Drastic sensitivity enhancement in 29Si MAS NMR of zeolites and mesoporous silica materials by paramagnetic doping of Cu2+.
abstract: The paramagnetic doping of Cu(2+) in both mesoporous silica materials and microporous silicate crystals (zeolites) can be used effectively to enhance the signal intensity of (29)Si solid state magic angle spinning NMR, as a result of shortening of the spin-lattice relaxation time, T1, by the paramagnetic effect, because of the Cu(2+) electronic relaxation time in the range of 10(-8) s. This leads to drastically reduced data-collection times, typically 80-fold shorter than that in mesoporous silica. We found that the estimated range of the paramagnetic effect of Cu(2+) doping in porous silicates was at least 1 nm.
authors.affiliation: Division of Materials Science and Chemical Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan. sinagaki@ynu.ac.jp
authors.forename: Satoshi
authors.initials: S
authors.lastname: Inagaki
authors.forename: Izuru
authors.initials: I
authors.lastname: Kawamura
authors.forename: Yukichi
authors.initials: Y
authors.lastname: Sasaki
authors.forename: Kaname
authors.initials: K
authors.lastname: Yoshida
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kubota
authors.forename: Akira
authors.initials: A
authors.lastname: Naito
mesh_terms: D003300:Copper / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D010316:Particle Size; D016062:Porosity; D012825:Silicon / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D013499:Surface Properties; D017641:Zeolites / Q000737:chemistry*
chemical_list: D017641:Zeolites; D012822:Silicon Dioxide; D003300:Copper; D012825:Silicon